Adjustable screen diaphragm for tube mills, etc.



l? 1931- w. A. GIBSON 1,825,347

ADJUSTABLE SCREEN DIAPHRAGM FOR TUBE MILLS, ETC

Filed om. 15, 1950 lnvenTcm WiHiQm A. Gibsnn by aw @M4 M ArTys.

Patented Sept. 29, 1931 UNITEDSTATES PATENTQFFICE A, GIBSO or .ALLENTOWN, PENNSYLVANIA; AssreNon To BRADLEY run VERIZER COMPANY, or ALLENTOWN, PENNSYLVANIA, A coeron'erron or Maser...

CHUSETTS I ADJUSTABLE SCREEN- DIAPHRAGM ron- TUBE M LLS, ETC.

Application filed October 13, 1930. Serial No. 488,331.

Thls 1nvent1on relates to improvements in tube mills of the compartment type which comprises a rotatable drum having at one end an inlet for the material to be ground, and

533 at the other end an outlet for the ground material, the drum being divided into aseries of compartments by screen diaphragms.

The several compartments of such mills are provided with grinding members, such as @130 pebbles, balls, rods, 'etc., to facilitate the grinding operatin,.the grinding members in the first or initial grinding compartment at the inlet end of the drum being relatively large, with successively smaller grinding members in the respective succeeding com- .partments. 1 a

i In order to providea maximumefliciency of grinding operation for ditterent'materials;

the relative lengths of the successive grindccg ing compartments desirably is varied in accordance with the. characterot the material to be ground. This requires an adjustment of the position of the diaphragms which separate one compartment from the next.

In tube mills of this type the drum is provided with a lining :of wear-resistant ma+ terial, and in usual constructions thedia-v phragms, which separate the several compartments fromv one another, extend to the interior surface ot the drum proper, so that the ends of the liningoteach compartment abut against the faces of the respective diaphragms. In order, theretore,to adjust the position of the diaphragms it is necessaryto remove the lining and to vary thelength of the lining for. the several compartments .in

accordance with the desired length ofQSuch ass compartments. This requires the removal of I the greater part of the lining of the mill,

The principal object of the present'invention is to provide a tube mill construction in which the diaphragms may bereadily adjusted to provide successive compartments of desirable relative lengths. 1 V A further object of the invention is to provide'a drum with a lining presenting an interior surface. of such character as to permit the adjustment of the diaphragms, and which will prevent rotation of thediaphragms rela 150 tive y to t e drum These and other objects and featuresot'the invention will more ,fully appear from the following description and the accompanying drawings and will be. particularly pointedout in the claims. 1

In the drawings: v i i c Fig. ,1 is a vertical longitudinalsectional yiew-ot a tube mill embodying the inven on; g Fig. 2is a transverse detail sectional view on line 22 Fig. 1, viewed trom theleft toward the-right; an p Fig. 3 is a fragmentary view illustrating the diaphragm adjustably mounted upon a hollow shaft. 1

The grinding mill, which is illustratedin the accompanying drawings, comprises .2. cy-

lindrical drum 1, having at its ends heads 2 and 3 provided respectively with preferably integral hollow trunnions 1; and 5which are mounted in suitable, .preterablyhollow, bearings 6 and 7. The end-s of the drum are secured to the heads by angle plates 8 and 9 which are welded, riveted, bolted, or other.-

wise secured to the drum and to the head.

A driving gear 10, which is secured tothe angle plate 9, is actuated by a: pinion (not shown) driven in any suitablemanner as is usual in such constructions. 1 7

The hollow trunnion 4 providesan inlet through which the materialto beground is introduced into the drum, and the hollow trunnion 5 provides an outlet through which drum. v

Any suitable means may be provided for introducing the material into the inlet trunnion of the drum. In the construction illustrated a scoop 11, which is connected to the end of the hollow inlet trunnion 4, and has a mouth 12 adapted to pass throughav teed I the several compartments, comprise circular the ground material is delivered from-the screen plates, or pairs of narrowly separated screen plates, the peripheries of which contact with the inner face of the cylindrical wall of the drum, and the linings of the several compartments abut at their ends against the opposite faces of the diaphragms; The diaphragms, therefore, are in fixed position and cannot be adjusted without removal and replacement of the greater portion of the lining. The present invention provides means for permitting adjustments of the diaphragms longitudinally of the drum to vary the relative length of the compartments without the necessity of removing and replacing any portion of the lining. This is accomplished by providing a rigid member extending longitudinally of and co-axially with respect to the drum and rigidly secured thereto by suitable spiders, or other supports, and slidably mounting the diaphragmupon said rigid member.

In the construction illustrated in the drawings this is accomplished by providing a central shaft 15 which may be a solidshaft, as illustrated in Fig. 2, or a hollow shaft 1500, as illustrated in Fig. 3. The shaft extends axially of the drum and is secured to the drum by spiders 1G and 17 which in turn are rigidly secured respectively within the hollow inlet andoutlet trunnions 4 and 5.

Other spiders may be employed within the drum if desired, or if necessary by reason of the length of the drum to support the shaft rigidly therein.

The diaphragms are slidably mounted upon the shaft 15 and desirably are provided with hubs with suitable means for securing the hubs of the diaphragm to the shaft in any desired adjusted position.

In order further to secure the diaphragm against rotation relatively to the drum, the drum is provided with a lining having ribs extending longitudinally of the drum in parallelism with the axis thereof, and the peripheries of the diaphragms are provided with recesses complementary to the ribs acting, when in engagement with the ribs, positively toprevent any relative rotative movement between the diaphragm and the drum.

In the preferred construction illustrated the lining comprises a series of longitudinally extending cylindrical sector-shaped plates 18, of wear-resistant material, fitting within the drum to provide a continuous lining therefor. Preferably each of t is lining plates 18 is pro vided with a central rib 19 having inwardly inclined edges 20 and a flat central face 21 The screen diaphragm may consist of a fiat circular plate 22 having a periphery complementary to the ribbed surface of the libing and with the central hub 23, which is adjustably mounted upon the shaft 1.5 or 15:13, or the diaphragm may comprise a pluralityof parallel, narrowly spaced, screen plates 24 connected together with suitable separators therebetween and having respectively peripheries complementary to the ribbed inner surface of the lining of the drum.

Desirably the circular diaphragms may be constructed in sections as quadrants 25 having circular peripheries 26 and secured by welding, or otherwise, to central hubs 27 slid-.

ably fitted upon the shaft 15. The hubs of the diaphragms may be secured to the shaft in any suitable manner as by a key 28, mounted in suitable key-ways extending longitudinally of the shaft and the hub, or by set screws 29, or other suitable fastening means.

For convenience in construction, sectorshaped plates 30, provided with recesses'31 complementary to the ribs 19, may be secured to the peripheral face or faces of the diaphragms by rivets 32, the rivets 32 extending also through suitable spacers if the diaphragms are provided with a plurality of narrowly separated screen plates. 3 I

The peripheral plates 30, by overlapping the abutting edges of the sections of the diaphragm plates to which they are secured, serve to strengthen the diaphragm construc tion.

If desired the single diaphragm construc tion 22, illustratedin Fig. 1, may have a circular periphery with plates having'recesses complementary to the ribs 31 of the lining secured to one or both faces of the plates as illustrated in Fig. 2.

By reason of such constructions the screen diaphragms may be adjusted to provide compartments of any desirable relative length, thereby providing the proper length of the respective compartments to cause the material travelling through the drum to be retained in the compartment until'it is subjectedtothe desired pulverizing action of the particular balls, or other grinding members of such compartment.

By reason. of the present invention, therefore, the adjustment of the diaphragms may be easily and quickly made to enable the'mill to operate at a maximum efficiency upon any particular kind of material.

Furthermore, by reason of the present invention the relative length of the compartments maybe quickly adjusted without the necessity of removal or replacement of any portion of the lining, thereby saving a very considerable cost in labor and materials which otherwise would be required to permit such adjustment in mills of usual types.

Having thus described the invention, what is claimed as new, and desired to be secured by Letters Patent, is: p

1. A tube mill comprising a rotatable drum having at one end an inlet for the material to be ground and at the. other end an outlet for the ground material, a rigid member secured to said drum and extending axiallv thereof, a screen diaphragm dividing the drum into a plurality of grinding compartments, means for adjustably securing said diaphragm to said rigid member in different positions longitudinally of the drum, whereby the relative lengths of adjacent grinding compartments may be varied, and complementary means upon the periphery of the diaphragm and the inner face of the drum for preventing relative'rotative movement between said diaphragm and said drum.

2. A tube mill comprising a rotatable drum having at one end an inlet for the material to be ground and at 'the other end anoutlet for the ground material, a rigid member extending axially thereof, a transverse screen diaphragm having a hub slidably mounted said drumcomprising a circular series of V wear-resistant plates having ribs extending longitudinally of the drum in parallelism with the axis thereof, a plurality of screen diaphragms having peripheral members 5;

In testimony whereof, I have signed my name to this specification.

WILLIAM A, eIBsou. 7

upon said rigid member, means for securing said hub to said rigid member in adjusted positions longitudinally of the drum to vary the relative lengths of adjacent compartments, and complementary interengaging members upon the periphery of the diaphragm and upon the inner surface of the drum operable to permit adjustment of the a diaphragm longitudinally of the drum, but

to prevent relative rotation therebetween.

3. A tube mill comprising a rotatable drum having at one end an inlet for the material to be ground and at the other end an outlet for the ground material, a shaft rigidly secured to said drum and extending axially thereof, a wear-resistant lining for said drum having a plurality of longitudinally extending ribs, a transverse circular screen diaphragm formed of sections lying in the same plane and having a hub slidably mounted upon said shaft, a circular series of peripheral plates secured to said drum overlapping the abutting edges of said sections and secured to said sections,- and presenting edges complementary to and slidably fitting the ribbed surface of said lining, and means for securing said hub to said shaft.

4. A tube mill comprising a rotatable drum having at one end an inlet for the material to be ground and at the other end an outlet for the ground material, a rigid member secured to said drum extending axially thereof, a wear-resistant lining for said drum having a plurality of ribs extending longitudinally of said drum in parallelism with the axis thereof, a transverse circular screen dia phragm having a hub slidably mounted upon said rigid member and provided with a circular series of peripheral plates presenting edges complementary to and slidably fitting Cir the ribbed surface of said lining, and means for securing said hub to said rigid member.

5. A tube mill comprising a rotatable drum having at its ends hollow trunnions providing respectively an inlet for the material to be ground and an outlet for the ground material, a shaft extending axially of said drum mounted at its ends in spiders fixedly secured within saidhollow trunnions, a lining for 

